Modern communication systems have benefited from advancements in communication technologies. When implemented in existing communication systems, such advancements provide for improved communications, e.g., more efficient communication of data, communication of data at higher communication rates, or in manners that better provide for the successful communication of the data in adverse communication conditions. And, advancements in communication technologies have permitted the development of new types of communication systems, providing for the effectuation of new types of communication services, and providing for better user experiences. As advancements in communication technologies shall likely continue, their implementation into existing and yet other new communication systems shall likely also continue in the future.
Communication systems are regularly utilized by many, and, for many users, ready access to communicate by way of any of various communication systems is necessary. Data is communicated upon a communication system by a user both to send data to another location and to receive data that is sent from a remote location.
Advancements in digital communication technologies are amongst the technological advancements that have been implemented in communication systems. Use of digital communication techniques provides various communication advantages. For instance, improved communication efficiencies are provided as redundancies in data that is to be communicated are removed prior to communication of the data. By improving the communication efficiency, the throughput rate of the data in the communication system is increased, relative to the throughput rate permitted of a corresponding analog communication system.
A radio communication system is an exemplary type of communication system. In a radio communication system, communication stations operable therein send and receive data communicated upon radio communication channels. The radio communication channels are defined upon portions of the electromagnetic spectrum. Free of the need to interconnect communication stations by way of wireline connections, radio communication systems permit for the effectuation of communications between locations at which interconnection of communication stations by way of wireline connections would not be possible or practical. Additionally, a radio communication system is implementable as a mobile communication system providing communication mobility to the communications.
A cellular communication system is an exemplary type of radio communication system. A cellular communication system includes a network part, referred to as network infrastructure, that is installed over a geographical area that is encompassed by the communication system.
Cellular communication systems generally conform to operational parameters set forth in an operating specification. Operating specifications are promulgated by standard-setting, regulatory bodies. And, the regulatory bodies have promulgated successive generations of operating standards, each generation taking advantage of advancements in communication technologies.
The network infrastructures of more than one generation of cellular communication systems might well be installed to encompass common geographical areas. And, the network infrastructures of cellular communication systems of the same generation, operated, e.g., by different network operators, might also be installed over a common geographical area.
Different cellular communication systems are of different communication capabilities and, accordingly, service availabilities. That is to say, different ones of the communication systems support different communication services. For instance, while so-called first generation cellular communication systems generally provide primarily voice communication services and only limited data communication services, subsequent generations of cellular communication systems provide for increasingly-intensive data communication services. An exemplary second-generation communication system, a GSM (Global System for Mobile communications) communication system provides for some data communication services. An extension to the GSM system, referred to as GPRS (General Packet Radio Service) permits for the effectuation of significantly more data-intensive communication services.
Even though the coverage areas of more than one cellular, or other, communication system might encompass a common geographical area, the different systems might exhibit different communication characteristics and capabilities. A communication service might be effectuable in one of the communication systems and not another. That is to say, different communication systems support different services and exhibit different services availabilities. A service supported in one communication system might not be supported in another communication system. And, when a mobile node is positioned within the coverage area of the radio network of a radio communication system, a communication service can only be effectuated by way of the network if the network supports the communication service. And, when the mobile node is positioned at a location encompassed by a plurality of radio networks, selection of by way of which network to communicate pursuant to effectuation of a selected communication service must be appropriately made in order for the communication service to be effectuated.
A mobile node generally accesses a service offered by a radio network to communicate therethrough by way of a registration procedure. During a registration procedure, signaling between the radio network and the mobile node is carried out, and, if the registration is successful, the mobile node gains access to the service carried over the radio network to communicate therethrough. Conventionally, the mobile node is unable to determine the availability of services in the network until the registration is completed and the mobile node accesses the network. If, subsequent to registration, the mobile node determines that the desired communication service is not supported by the network which the mobile node is accessing, the mobile node is withheld of the communication service or the mobile node attempts registration with another radio network, and the process is repeated.
In essence a trial and error process is carried out that requires signaling between the mobile node and each network with which the mobile node registers, potentially introducing significant delay periods prior to effectuation of the communication service.
If a manner could be provided by which better to identify the service availability of a radio network, a communication service could be carried out more efficiently.
It is in light of this background information related to communications in a radio communication system that the significant improvements of the present invention have evolved.